A simple method of facility expansion (e.g., as in the case of schools) includes the use of free-standing trailers or mobile office units that have been pre-fabricated and delivered to a site. While these units include their own climate control and lighting systems, and lend themselves to quick set-up, they also present a variety of problems. For example, the occupants have to walk outside when moving between the existing facility and the mobile unit(s). In addition, the nature of mobile units prevent them from being large enough to serve as a library, cafeteria, or other large facility space that must be shared by all occupants. Accordingly, while the use of mobile units provides for additional occupants, the existing shared facility spaces might not be designed to accommodate the additional occupants. Further, the mobile units are not generally compatible with the existing facility architecture and are often considered to be an eyesore. Combining this perception with the fact that the occupants are isolated from the main existing facility can lead to poor morale for the occupants relegated to the mobile units. Still further, the mobile nature of these units makes them more susceptible to storm and wind damage thereby possibly placing the occupants thereof in peril in the event of unexpected bad weather.